Safety gate



NOV. 6, 1934. w w c s m ET AL 1,979,369

SAFETY GATE Filed Sept. 2, 1933 2 Sheets-Sheet 1 ill-mentors [Gilliam11]- Bushlgg Hubert K-PE.I.IHBI" 1934- w. w. CUSHING El AL 69 SAFETYGATE Filed Sept. 2, 1935 2 Sheets-Sheet 2 hluantnrs UJllllEHl'L U]-Eushmg Hobart PLP-almar Patented Nov. 6, 1934 UNITED STATES SAFETY GATEv William Whelan Cushing and Robert Kendrick Palmer, Hamilton,.0ntario,Canada Application September 2,.1933, Serial No. 687,970

8 Claims. (01.:39-8) Our invention relates to improvements in safetygates as are used on highways at level railroad crossings, ends ofmovable bridges, etc., and the object of our invention is to furnish avery simple and positive gate actuating mechanism which can beconstructed and installed at a comparatively low cost and which willrequire very little attention.

A further object of our invention is to incorporate a hydraulicallyactuated piston in. our gate actuating mechanism for imparting movementto the gate, and also to furnish a simple gate" locking device whichwill positively retain the gate in either the open or closed positionand which can be released with a negligible power consumption.

Our invention consists of a gate constructed and arranged all ashereinafter more particularly described and illustrated in theaccompanying drawings in which I i Fig. 1 is a plan view of thehousingin which our gate mechanism is contained, showing the inner endportions of the gates supported thereby, the gates being in the downwardor closed position.

Fig. 2 is a side elevational view of the gate mechanism housing showingthe gates in full lines .in the up or open position, and in dotted linesin the downward position.

Fig. 3 is a vertical cross sectional view through the housing andmechanism wherein the gates are in the open position.

Fig. 4 is a similar view to Fig. 3, showing the position ofthelmechanism with the gates in. the 35' closed position.

Fig. 5 is a transverse cross sectional view through the housing andmechanism, being taken through the line 55, Fig. 4.

.Fig; 6 is a horizontal-cross sectional view taken 1 ,through the upperportion of thehousing and mechanism, showing the gate supporting shafts,

and

i Fig. '7 is'a perspective view of a pair of lcam plates which wefurnish as the gate lockingimeans.

uLike characters of reference indicate corre- -.sponding}parts in thedifferent views in .the draw- -ings. i

The gate consists of the usual wooden arms-1 60 and 2 for the roadwayand sidewalk respectively.

The inner end of the arm 1 is of bifurcatedform -.andis bolted to apairof' swingable members 3 carried upon the ends of a cross? shaft4:exteriorply of the mechanism housing 5. Thewmembers are furnished withthe usual counter-weights 6.

tion of the motor 25, the oil ispumped from tone end of a shaft 8 lyingparallel to the shaft 4 and protruding from the housing 5. The rotatorymovement of the shafts 4 and 8 swing the arms from the horizontal tovice versa.

The shafts 4 and 8 carry a pair of segmental gears 9 andIO which arekeyed thereto in positions opposite one another.

The segmental gears 9 and 10 mesh with a vertically "reciprocable rack11 having teeth upon the sides thereof with which the gears engage. Therack is formedwith a central slot 12 through which a supporting pin 13extends, the pin being carried 'between a pair of transversely extendinghorizontal supporting plates 14 through which the shafts 4 and 8 freelyextend. The provision of the pin 13 within the slot 12 limits therecipthe vertical positions and rocable movement of the rack and alsofurnishes a support for the rack when it is in the lowermost position,as illustrated in Fig. 3. The lower end of the rack is of substantiallycircular cross section and is formed with a bore 15 extending upwardlyfrom its lower end to receive the upper end of a piston rod 16 whichslidably protrudes thereinto. The piston rod is permitted a slidingmovement'within the bore 15, and to limit such sliding movement weprovide the bore portion of the rack with a pair of diametricallypositioned vertical slots 17 which receive the ends of a cross pin 18extending through the upper end of the piston rod. The piston rod has amovement in the bore limited by the movement of the pin within the slots1'7.

The piston rod 16 protrudes from a cylinder and piston assembly 19and 20which is suitably supported by a plurality of angles 21 extending acrossthe lower'portion of the housing.

The cylinder 19 is filled with fluid such as oil and in order toreciprocate the piston 20, we furnish an oil pump 22 which communicateswith the-upper and lower ends of the cylinder through pipes23 and 24.The pump 22is of the reversible type and .is actuated by an electricmotor 25' whichis also of the reversible type and connected to the pumpthrough the medium of a belt 26 extending over the pump and motorpulleys 27 and 28. By reversing the direction of rotaendof the cylinderto the other with the result- '105 ant actuation of the piston 20.In-order to pro vide for any over-run of the motor-afterothe piston hasbeen moved from one. end of the-cylinder to the other, we furnish aby-pass oil pipe V 29 extending from the pipes 23 and 24 around thepump. The by-pass pipe is furnished with a hand adjusted valve 30 whichpermits the contained oil to leak past when a certain oil pressure hasbeen reached, so that, if the motor 25 should continue to run after thepiston has reached the end of its movement, the pumped oil will thenby-pass through the pipe 29.

For locking the rack 11 at the upper and lower ends of its travel, wefurnish a pair of gravity actuated cam weights 31 which are pivotallymounted upon the pin 13 upon either side of the rack and pinions. Thesecam weights are of the same size and form and each consists of an uppersubstantially vertical portion 32 formed with a horizontal land edge 33upon its top and a slot 34 in the vicinity of its lower end, The upperend of the rack 11 is formed with two horizontally protruding lips 35,such lips being adapted to rest upon the lands 33 when the rack is inthe uppermost position, and to abut against the upper faces of the slots34 when the rack is in the lowermost position. In order to permit therack to reciprocate, the upper ends 32 of the cam weights are swung inthe direction of the arrows shown in Figs. 3 and l. For swinging theupper cam weight portions 32, we form the lower weight portions of thecam weights of enlarged size and of such dimensions that their edges 36are of substantially V form and are engaged by the protruding ends ofthe cross pin 18, the apexes of the edges 36 normally lying beyond oneside of the rack 11 and the major portion of the cam weights lying atthe other side of the rack. The cam weights are, of course, so designedthat they have sufficient clearance in their swinging movement.

The operation of our device is as follows:-

When our device is in the position illustrated in Fig. 3, the gates areopen, i. e. the arms 1 and 2 are substantially vertical, the segmentalgears 9 and 10 downwardly inclined and the rack 11 and piston 20 at thelower ends of their movements. When it is desired to close the gates,the current actuating the motor 25 is switched on, either manually orautomatically through the approach of a train, as is the case inrailroad crossing gates. The rotation of the motor actuates the pump 22to pump oil from the upper end'of the cylinder through the pipes 23 and24 into the lower end of the cylinder and move the piston 20 and thepiston rod 16 upwardly. As the cross pin 18 extending through the pistonrod and the lower portion of the rack is at the lower ends of the slots17, the piston rod is permitted an initial free upward movement withouta corresponding movement of the rack. When this initial movement of thepiston rod occurs, the pin 18, the ends of which bear against the Vedges 36 of the cam weights, moves upwardly and in bearing against andmoving along such V edges swings the lower portions of the cam weightsabout the supporting pin 13 in a clockwise direction, as shown in Figs.3 and 4, with the resultant swinging movement of the upper ends 32 ofthe cam weights, as shown by the arrows. Before the cam weights aremoved the lips 35 upon the upper end of the rack 11 are contained withinthe cam weight slots 34 and the rack locked against movement. When theupper ends 32 of the cam weights are swung the slots 34 becomedisengaged from the lips and when the cross pin 18 reaches the upper endof the slots 17 the rack 11 is free to move upwardly with the pistonrod.

As the ends of the pin 18 in their upward movement pass around theapexes of the cam edges 36,

the cam weights have a return swing in a counterclockwise directionunder their own weight, and by the time the rack has reached the upperend of its stroke, as illustrated in Fig. 4, the landings 33 at theupper ends 32 of the cam weights swing into a position beneath the racklips 35, thus retaining the rack against downward movement and holdingthe gears 9 and 10 in the up position and the gates in the horizontal orclosed position.

When the gates are to be opened, the motor 25 is rotated in the reversedirection, causing the fluid to pass from the lower to the upper part ofthe cylinder 19 with the resultant downward movement of the piston 20,piston rod 16 and cross pin 18 within the slot 17. As previouslyexplained, the outer ends of the cross pin 18 ride against the v edges36 of the cam weights, so that when the pin travels downwardly inconjunction with the piston rod its downward movement causes the camweights to again swing in a clockwise dire ction'wherein the lands 33swing from underneath the rack lips 35. When the pin 18 reaches thebottoms of the slots 17 the lands 33 of the cam weights have movedcompletely from underneath the lips 35, and the further downwardmovement of the piston rod pulls the rack downwardly, thus causing thesegmental gears 9 and 10 to swing in a clockwise direction with theconsequent partial rotation of the shafts 4 and 8 and swinging movementof the gates into the open position as shown in Fig. 3.

It will be apparent that the provision of the cam weights engaging thelips on the rack provides a positive means for retaining the rack ineither the upward or downward position as the case may be and thatthrough the provision of the free reciprocable movement between thepiston rod and the rack during the initial stages of operation for thepurpose of swinging the cam weights out of the rack engaging positionthat we have provided a very simple and positive mechanism. If at anytime the pump mechanism should go out of order, or the electricalcurrent supply be cut off, and it is desired to use the gates, thehousing door may be opened, the cam weights manually swung into theunlocked position and the gates moved upwardly or downwardly by hand.Although we have shown a particular embodiment of our invention, it isto be understood that we can at any time make any changes that we maysee fit without departing from the spirit of our invention as set forthin the appended claims.

What we claim as our invention is:

1. In a level crossing gate for railroads and the like incorporating avertically swingable gate arm, the combination with a piston, piston rodand cylinder assembly constituting the arm swinging power means and areciprocable element slidably coupled to the piston rod and geared tothe swingable arm, of a swingably mounted cam member swung by the pistonrod in its travel and adapted to engage and lock the reciprocableelement at the ends of its stroke, and a pin projecting from the pistonrod and slidably contained within a slot in the reciprocable element toconstitute the slidable coupling between the piston rod and thereciprocable element and also adapted to engage the cam face of the cammember.

2. In a level crossing gate for railroads and the like incorporating avertically swingable gate arm, the combination with a piston, piston rodand cylinder assembly constituting the arm swinging power means and areciprocable element slidably coupled to the piston rod and geared tothe swingable arm, of a swingably mounted cam member swung by the pistonrod in its travel and adapted to engage and lock the reciprocableelement at the ends of its stroke, and a pin projecting from the portionof the piston rod contained within the bore into a slot within the boreportion of the reciprocable element to constitute the slidable couplingbetween the piston rod and the reciprocable element and also adapted toengage the cam face of the cam member.

3. In a level crossing gate for railroads and the like incorporating avertically swingable gate arm, the combination with a piston, piston rodand cylinder assembly constituting the arm swinging power means and aslotted reciprocable element slidably coupled to the piston rod andgeared to the swingable arm, of a swingably mounted cam member swung bythe piston rod in its travel and adapted to engage and lock thereciprocable element at the ends of its stroke, and a pinprojectingthrough the slot in the reciprocable member to limit its movement andalso constituting the pivotal point about which the cam member swings.

4. In a level crossing gate for railroads and the like incorporating avertically swingable gate arm, the combination with a piston, piston rodand cylinder assembly constituting the arm swinging power means and areciprocable element slidably coupled to the piston rod and geared tothe swingable arm, of a gravity actuated swingably mounted cammemberswung by the piston rod in its travel and adapted toengage and lock thereciprocable element at the ends of its stroke.

5. In a level crossing gate for railroads and the like incorporating avertically swingable gate arm, the combination with a piston, piston rodand cylinder assembly constituting the arm swinging power means and aslotted reciprocable element slidably coupled to the piston rod andgeared to the swingable arm, of a gravity actuated swingably mounted cammember swung by the piston rod in its travel and adapted to engage andlock the reciprocable element at the ends of its stroke, and a pinprojecting through the slot in the reciprocable member to limit itsmovement and also constituting the pivotal point about which the cammember swings.

6. A level crossing gate for railroads and the like comprising avertically swingable gate arm, a piston, piston rod and cylinderassembly constituting the arm swinging power means, a reciprocable racksubstantially moving in unison with the piston rod and geared to theswingable arm, a rockable gravity actuated cam member rocked by thepiston rod in its travel, and a member projecting from the rack andadapted to engage with the cam member and be releasably retained by thecam member against movement at the ends of the racks stroke.

7. A level crossing gate for railroads and the like comprising avertically swingable gate arm, a piston, piston rod and cylinderassembly constituting the arm swinging power means, a reciprocableslotted rack substantially moving in unison with the piston rod andgeared to the swingable arm, a rockable gravity actuated cam memberrocked by the piston rod in its travel, a member projecting from therack and adapted to engage with the cam member and be releasablyretained by the cam member against movement at the ends of the racksstroke, and a pin projecting through the slot in the reciprocable memberto limit its movement and also constituting the pivotal point aboutwhich the cam member rocks.

8. A level crossing gate for railroads and the like comprising avertically swingable gate arm, an arm swinging reciprocable element, agear connection between the element and the gate, gravity actuated cammeans for releasably engaging the element to lock the gate both in theopen and closed positions, a piston, piston rod and cylinder assemblyconstituting the reciprocating power means, coupling means between thepiston rod and the reciprocable element, a power driven fluid pump,fluid pipes extending from the pump to the ends of the cylinder, aby-pass pipe extending between the pipes around the pump, and anadjustable fluid passage valve contained within the by-pass pipe.

WILLIAM WHELAN CUSHING. ROBERT KENDRICK PALMER.

